Premium
P3‐160: Implications of better signal: Noise properties of 18F NAV4694 PET amyloid imaging for visual interpretation and scan quantitation
Author(s) -
Seibyl John P.,
Kuo Phillip,
Reininger Cornelia
Publication year - 2015
Publication title -
alzheimer's and dementia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.713
H-Index - 118
eISSN - 1552-5279
pISSN - 1552-5260
DOI - 10.1016/j.jalz.2015.06.1531
Subject(s) - precuneus , white matter , grey matter , posterior cingulate , nuclear medicine , medicine , neuroimaging , psychology , radiology , neuroscience , magnetic resonance imaging , functional magnetic resonance imaging
Background: 18F NAV4694 PET imaging in Alzheimer patients demonstrates higher brain specific uptake with greater cortical grey matter uptake relative to white matter than the current generation of F-18 amyloid radiotracers available for clinical use. In particular, visual patterns demonstrate intense focal uptake in posterior cingulate/precuneus, frontal cortex, and caudate. The clinical relevance of higher signal to noise is unknown. The objectives of this study are: 1) to correlate 18F NAV 4694 scan with clinical data and PET quantitation, 2) to compare quantitative analyses with and without gray/white matter segmentation. Methods: 107 NAV4694 PET images from two multicenter trials recruiting healthy volunteers, MCI, and AD participants were visually read by a consensus panel of three experienced experts who documented different scintigraphic patterns of cortical uptake. These features were compared with clinical and demographic data and regional SUVr measurements obtained both with and without individually derived MRI grey matter correction maps. Results: Fifty scans were consensus negative and 57 positive with nearly unanimous agreement among readers. Mean age and MMSE scores were 62.6 +/19.2 y and 27.5 +/3.0, respectively, for the negative scans, and 73.6 +/-6.3 and 24.7 +/4.7, respectively, for the positive studies. SUVrs were correlated with MMSE (-0.4629, p< 0.0001) in positive scan subjects. Mean SUVrs were 2.2 +/0.4 and 1.3 +/0.1, respectively, for the positive and negative scan cases. There were no differences in either composite or individual regional SUVrs when MRI-derived segmentation was performed. Features associated with higher composite SUVrs were high caudate and/or precuneus uptake and “super scans” (higher gray matter uptake than adjacent white matter). Conclusions: 18F NAV4694 is a promising next generation amyloid PET tracer with high signal: noise, reflected in more focal cortical uptake with easier visual interpretation, robust quantitative properties, and possibly simpler image processing algorithms which are not reliant on a concomitant MRI to reduce white matter contamination of SUVr.